The primary outcome variable will be insulin sensitivity, which will be calculated minimal model analysis of the IVGTT insulin and glucose data. Insulin sensitivity will be compared among baseline, 2 week and 8 week testing times by repeated measure ANOVA. Secondary outcome measures will be first phase IVGTT insulin response, IVGTT incremental insulin area between 0-240 minute3s, and the OGTT glucose and insulin total areas (trapezoid method).